A drive device for motor vehicles, for driving a vehicle axle of a motor vehicle with two wheels in active connection with one another via two planetary gearsets is known from DE 10 2006 031 089.6. The first planetary gearset is designed as a so-termed stepped planetary gearset with stepped planetaries, whereas the second planetary gearset is a so-termed positive planetary gearset with shiftable reversing stages. In each case a shaft of a planetary gearset can be brought into active connection with a driveshaft connected to a wheel or with an output shaft of the drive device. Moreover a shifting mechanism is provided, by means of which a first power path or a second power path between the wheels of the vehicle axle can be engaged.
In the area of a further shaft of the planetary gearsets, torque of an electric machine can be passed into the first or the second power path. The torque of the electric machine can be transferred in equal parts and with the same sign to the output shafts or wheels of the vehicle axle when the first power path is engaged, and in equal parts but with opposite signs when the second power path is engaged, in order, during a first operating mode, to provide a drive torque in the area of the vehicle axle, or during a second operating mode, to improve the driving behavior of a motor vehicle by distributing the torque produced by the electric machine in equal parts but with opposite signs between the wheels of the vehicle axle and transmit them thereto.
The electric machine is arranged coaxially with a driveshaft connected to a carrier of the stepped planetary gearset, by means of which torque can be transmitted to one of the drive wheels of the vehicle axis, and between the stepped planetary gearset and the drive wheel in an area of a motor vehicle in which the structural space available for fitting an electric machine is limited. For that reason the drive device can disadvantageously only be made with electric machines which take up no more space than is available and whose power is therefore insufficient for various requirements.